Stringed instrument neck construction



Dec. 31, 1968 J. DOPYERA STRINGED INSTRUMENT NECK CONSTRUCTION Filed Feb. 15, 1967 MHENTOR JOHN DOPYERA BY EDWARD D. OER/AN ATTORNEY United States Patent 3,418,876 STRINGED INSTRUMENT NECK CONSTRUCTION John Dopyera, 1206 S. Escondido Blvd., Escondido City, Calif. 92025 Continuation-impart of application Ser. No. 524,196, Feb. 1, 1966. This application Feb. 15, 1967, Ser. N0. 616,317

- 7 Claims. (Cl. 84293) ABSTRACT OF THE DISCLOSURE A resilient metallic bar is positioned within a rectangular opening through the neck of a stringed instrument beneath the fingerboard thereof. The bar is tapered at at least one end and adjusting screw means extends from the fingerboard side of the neck into the bar so that the bar may be bent to provide forces in opposition to the neck bending forces of the strings.

Cross reference This application is a continuation-in-part of patent application Ser. No. 524,196, filed Feb. 1, 1966, now abandoned.

Background This invention is directed to the construction of the necks of stringed instruments such as guitars. A resilient bending bar is positioned within the neck of the stringed instrument. This bar is ad-justably stressed with respect to the neck in such a direction as to counteract the bending forces of the string secured to the neck. The opening in the neck in which the bar is located is rectangular while the bar itself is tapered on one end to provide room for bending freedom within the neck.

Prior structures have attempted to overcome the problem of neck bending due to string stresses. The principal efforts in the past have included the use of a torque rod extending through the neck. This torque rod is interconnected to the ends of the necks so that torque therein results in stresses applied to the neck which supposedly counteract the string stresses. However, such torque rods necessarily include twisting force and thus when such a single torque rod is used, the neck twists as a result of the application of forces in opposition to the string forces. Further prior art structures include doubling of these torque rods so that the torque thereof is in opposition. Thus, the second torque rod is necessary to overcome the disadvantages occasioned by the first one. However, two of such torque rods provide excessive structure within the neck so that the openings required for the pair of rods necessarily weaken the neck. The present structure produces the necessary forces with a minimum of neck opening or channel so that neck integrity and strength is maintained.

Summary This invention is directed to stringed instrument neck construction and particularly to construction which includes a bending bar within the neck of the stringed instrument, which bending bar can be stressed to oppose the string stresses which ordinarily are imposed on the neck. It is necessary in stringed instruments to maintain the strings properly spaced with respect to the fingerboard of fretboard. When undefiected these strings must clear the frets, and string deflection must not be excessive for manual deflection of the strings onto the frets. Too much deflection makes it difficult to play such a stringed instrument and slows down the responsiveness of the instrument to the musicians fingering. String stresses bend the neck over a period of time to objectionably change the string-fret relationship. The bending bar of this invention is thus incorporated into the neck of the stringed instrument. The neck is provided with a rectangular channel of uniform cross section. The bar is set in this channel, and the top of the channel is closed by means of a spacer. Thereupon the fingerboard is placed over the top of the neck. This construction incorporates the bar firmly within the neck. The outer end of the bar is tapered on its side toward the fingerboard in a direction away from the fingerboard. The nut end of the bar extends past the nut and a screw extends from the surface of the neck outside of the nut and is threaded into the end of the bar. Thus, tightening of the screw causes upward bending of the outer end of the bar. This bending produces forces in the opposite direction to the bending forces caused by the tension of the strings.

The end of the bar toward the body of the stringed instrument can be either of uniform cross section and completely filling the channel, or alternatively it may also be tapered. In the latter case, a further screw passes through the face of the fingerboard and into the bar so that end of the bar can also be urged upward toward the fingerboard to produce bending stresses. By this construction it is seen that a stringed instrument neck can be readily formed and an inexpensive bar can be inserted therein to produce the proper force without any torquing or twisting of the neck of the stringed instrument. The use of a channel of uniform cross section within the neck simplifies the manufacture of the neck, as compared to neck channels which are not of uniform cross section. The tapering of the bending bar is a relatively inexpensive machining operation and is more convenient to carry on than the shaping of the channel in which the bar is placed. Furthermore, the placement of the main adjusting screw outside of the nut keeps the fingerboard clear of obstructions and differences in form and texture in the area where fingering primarily takes place.

Accordingly, it is an object of this invention to provide neck construction for a stringed instrument in which a bending bar is positioned within the neck, which bending bar is positioned in a channel of uniform cross section for ease of manufacture of the neck, and the bar is tapered at at least one end to provide bending room for the bar. It is a further object of this invention to provide adjustment of the bending bar outside of the nut on the neck of the stringed instrument so that the adjusting screw is positioned away from the usually fingered areas of the fingerboard. It is still another object of this invention to provide a bending bar which is economic of construction and easily installed and used so that the bending bar can be employed in the necks of stringed instruments to counteract the neck bending forces of the strings, and thus maintain proper distance between the strings and the fingerboard. Other objects and advantages of this invention will become apparent from a study of the following portion of this specification, the claims and the attached drawings.

Description of the drawings FIG. 1 is primarily a longitudinal sectional view, with part of the stringed instrument body shown in side elevation showing the stringed instrument neck construction of this invention.

FIG. 2 is an enlarged section taken generally along the line 22 of FIG. 1.

FIG. 3 is a partial enlarged longitudinal section of the nut end of the neck and of the bending bar.

FIG. 4 is a longitudinal section through a stringed instrument neck, similar to FIG. 1, showing a further embodiment of the stringed instrument neck construction of this invention.

FIG. 5 is an enlarged section, with parts broken away, showing the details of the body end of the bending bar and neck of the embodiment shown in FIG. 4.

FIG. 6 is atop plan view of the stringed instrument neck showing the adjusting screw and washer on the nut end.

Description A stringed instrument is illustrated at 10 in FIG. 1. The stringed instrument 10 is illustrated as a guitar, but it will be clear from the following that this is merely an example of a stringed instrument to which the neck construction of this invention is applicable. The stringed instrument 10 has a body 12 and a neck 14. Neck 14 is an elongated structure of such size that a hand can be grasped thereabout. Neck 14 is secured at its inner end to body 12 and its outer end carries nut 16. A plurality of strings 18 extend from a securing point on body 12, over a bridge on body 12, extend over neck 14 and over nut 16, and are individually secured to capstans at the outer end of neck 14. These capstans are conventional. It can be seen from this construction that tension of strings 18 can cause upward bending of the right end of neck 14.

Neck 14 comprises main neck member 20 and fingerboard 22. In the instrument illustrated, the fingerboard is provided with a plurality of frets 24 which extend upward from the fingerboard and are spaced below the strings 18. To change the effective vibration length in the strings 18, they are manually pushed down upon a selected fret 24 to thus change the vibrational frequency thereof. Of course, the ease of pressing and holding the string 18 against the selected fret determines the ease of fingering of the instrument. Furthermore, the strings must be clear of any frets toward the body 12 of the instrument against which they are not held. Any contact with another fret would cause dampening of the vibration of the strings and the consequent improper tone. Thus, the straightness of the neck 14 is of critical importance to proper play and proper tone.

In the preferred embodiment of the neck construction of this invention, as is seen in FIGS. 1 through 3, main member 20 has a rectangular channel 26 cut therein. The channel extends out of the end of neck 14 toward the body end and beyond the nut 16 on the nut end of the neck. Resilient metallic bar 28 is positioned within this channel. The metallic bar is preferably light and resilient Within the bending range. Many normal metallic materials are suitable for such service. Steel is suitable, and when a steel bar is used, the size of the bar need not necessarily be as large as that illustrated. Furthermore, in the interest of lightness, the suitable grade of aluminum can be used. Alloy 6061 treated to T6 is suitable for this purpose. Many other materials are equally suitable. From its midpoint 30 toward the body end of the neck, the bar is a full size rectangular section to completely fill the lower portion of rectangular channel 26. At its body end it is screwed into the neck by means of wood screw 32 which prevents endwise shifting of bar 28. From its midpoint 30 to the nut end of the bar, bar 28 is tapered down on the top surface. In its unstressed condition, bar 28 lies on the bottom of channel 26 as shown in FIG. 1. Due to the tapered surface 34, there is clearance in the channel above the bar. Spacer 36 is secured into the top of channel 26 to provide a rectangular channel which is the same size of the bar from the body end to center point 30. Fingerboard 22 is secured over main member 20 and spacer 36.

To the right of nut 16, as seen in FIG. 1 and 3, screw 38 passes through decorative washer 40 and is threaded into the right end of bending bar 28. Thus, as screw 38 is tightened, the right end of bending bar 28 is moved upward within channel 26 and screw 28 places a downward thrust atthe nut end of neck 14. Upward thrust is produced at the center point 30 by bending bar 28 against the spacer 36 in the neck. These forces counteract the bending forces produced by the tension of the springs 18 to maintain the neck in proper configuration even through a long stringed instrument life. Since the left end of bar 28 is solidly positioned within channel '26, the bending stresses produced by the bending of the right end of bar 28 produce comparable bending forces in the anchored end of the bar. Thus, the bending forces are properly distributed over the length of the neck.

In the embodiment shown in FIGS. 4 and 5, the stringed instrument 42 has a neck 44. Channel 46 is rectangularly formed through the neck from nut 48 to body 50, identically to the preferred embodiment described with respect to FIGS. 1 through 3. Channel 46 is a rectangular channel and extends past nut 48. Channel 46 is closed by means of spacer 52 and fingerboard 54 is secured over the neck main member and spacer 52. Frets 56 are positioned along the length of fingerboard 54. Strings 58 extend from the body of the guitar, over the fingerboard and frets and over the nut 48 to be secured to conventional tension adjusting capstans at the right end of the neck.

Resilient bar 60 is positioned within channel 46. Resilient bar 60 is of the same metallic construction as bar 28. It may be made of any resilient metallic material, such as steel or aluminum, and other suitable material as is described above. Resilient bending bar 60 has a midpoint 62, and at that point it completely fills the channel 46 up to the underside of spacer 52. As is seen at the right end of FIG. 4, the nut end of bending bar 60 has an upper tapered surface 64 and an adjustment screw 66 which extends through a decorative washer and is threaded into the right end of bending bar 60. Thus, the right end of bending bar 60 is identical to the right end of the bending 28. and FIG. 3 illustrates in more detail the same construction as shown at the right end of FIG. 4.

As contrasted to the structure of FIGS. 1 through 3, however, the embodiment of FIGS. 4 and 5 includes tapered surface 68 at the left end of bending bar 60 to the left of its mid point 62. Thus, there is space above the left end of bending bar 60 at the body end of the bar to provide for additional upward bending of that portion. Screw 70 has a head which is flat and is inset into the fingerboard 54 between frets thereon. Load distributing 'washer 72 is inset into the bottom of the fingerboard and spreads the load from the head of screw 70 to the main member of neck 44 and spreads it across channel 46, for washer 72 has a diameter larger than the width of channel 46. Screw 70 extends downward and is threaded into the left end of bending bar 60. Thus, either or both screws 66 and 70 can be tightened to bend the ends of bar 60 upward to produce an appropriate bending force within neck 44 to counteract the bending stresses produced by strings 58.

Since channels 26 and 46 are rectangular, they are easy to cut into the respective main bodies of the necks in order to prevent the channels from unnecessarily weakening the necks. Spacers 36 and 52 are placed in the upper parts of the channels. However, these spacers are also rectangular so that a rectangular passage through the neck is produced. The bending bars positioned in these channels are contoured in such a manner that stress on the bars causes bending thereof to produce the necessary forces counteracting the string forces. Thus, by use of the guitar neck construction of either of the embodiments of this invention a strong neck is provided and the structure within the neck can be adjusted to maintain neck straightness.

I claim:

1. A stringed musical instrument having a body, a neck extending from said body, a plurality of tensio-nable strings connected to an extremity of said neck remote from said body and to said body, said strings extending along and being spaced from said neck, and a fingerboard located on a surface of said neck adjacent to said strings 'wherein the improvement comprises:

a channel located in said neck so as to extend beneath said fingerboard from said body to adjacent the extremity of said neck remote from said body, said channel having an upper surface adjacent to said fingerboard,

a bending bar positioned within said channel, said bar being of resilient material and having ends located at the ends of said channel,

said bar contacting said upper surface of said channel between the ends of said bar and said channel,

the end of said bar remote from said body being spaced from said upper surface,

adjusting means for varying the spacing between the end of said bar remote from said body and the upper surface of said channel so as to cause deformation of said neck by altering the relative positions of the end of said bar remote from said body and the adjacent portions of said neck, and

holding means for holding the other end of said bar adjacent to said body with respect to said neck and said channel.

2. A stringed musical instrument as claimed in claim 1 wherein:

said channel is of a uniform cross-sectional configuration, and

said bar is tapered from the portion of said bar contacting said upper surface intermediate to the ends of said bar and said channel towards the end of said bar remote from said body.

3. A stringed musical instrument as claimed in claim 1 wherein:

said other end of said bar adjacent to said body is spaced from said upper surface and said channel, and

said holding means comprises other adjusting means for varying and spacing between said other end of said bar adjacent to said body and the upper surface of said channel.

4. A stringed musical instrument as claimed in claim 3 wherein:

both ends of said bar are tapered from the portion of said bar contacting said upper surface intermediate to the ends of said bar.

5. A stringed musical instrument as claimed in claim 1 wherein:

said bar and said channel both have a rectilinear crosssectional configuration.

6. A stringed musical instrument as claimed in claim 1 wherein:

said adjusting means comprises a screw engaged with said neck and threaded into said bar and a washer separating said screw and said neck.

7. A stringed musical instrument as claimed in claim 1 wherein:

the other end of said bar adjacent to said body is spaced from said upper surface and said channel,

said holding means comprises other adjusting means for varying spacing between the other end of said bar adjacent to said body and the upper surface of said channel,

both ends of said bar are tapered from the portion of said bar contacting said upper surface intermediate to the ends of said bar towards the ends of said bar,

said bar and said channel both have a rectilinear crosssectional configuration,

both of said .adjusting means comprises a screw engaged with said neck and threaded into said body and a washer for separating said screw and said neck.

References Cited UNITED STATES PATENTS 1,446,758 2/ 1923 McHugh 84-293 2,100,249 11/1937 Hart 84293 2,101,364 12/1937 Dopyera 84293 2,148,589 2/ 1939* Stathopoulo 84-293 2,510,775 6/1950 Forcillo 84--293 3,143,028 8/1964 Fender 84-293 3,159,072 12/1964 Burns et al 842-93 FOREIGN PATENTS 150,971 8/1950 Australia.

151,283 8/1955 Sweden.

248,509 2/ 1948 Switzerland.

RICHARD B. WILKINSON, Primary Examiner.

S. A. WAL, Assistant Examiner. 

